High performance two-phase cooling apparatus

Abstract

The present application discloses two-phase cooling devices that may include at least three substrates: a metal with a wicking structure, an intermediate substrate and a backplane. A fluid may be contained within the wicking structure and vapor chamber for transporting thermal energy from one region of the thermal ground plane to another region of the thermal ground plane, wherein the fluid may be driven by capillary forces within the wicking structure. The intermediate substrate may form narrow channels within the wicking structure, providing high capillary forces to support large pressure differences between the liquid and vapor phases, while minimizing viscous losses of the liquid flowing in the wicking structure.

The invention claimed is: 
     
       1. A thermal ground plane comprising:
 a metal substrate having a surface within a vapor chamber; 
 said vapor chamber in communication with said surface of said metal substrate; 
 an intermediate substrate within said vapor chamber having a first set of cross members in one direction and a second set of cross members in another direction connected to said first set of cross members, said first set of cross members being in a separate and adjacent plane from said second set of cross members, said first set of cross members defining channels between said cross members adjacent within said first set, and said second set of cross members defining channels between said cross members adjacent within said second set, said channels between said first set of cross members and said channels between said second set of cross members intersecting to form apertures bounded by said cross members; 
 a second intermediate substrate within said vapor chamber having a first set of cross members in one direction and a second set of cross members in another direction connected to said first set of cross members in said second intermediate substrate, said first set of cross members in said second intermediate substrate being in a separate and adjacent plane from said second set of cross members in said second intermediate substrate, said first set of cross members in said second intermediate substrate defining channels between said cross members adjacent within said first set within said second intermediate substrate, and said second set of cross members within said second intermediate substrate defining channels between said cross members adjacent within said second set within said second intermediate substrate, said channels between said first set of cross members in said second intermediate substrate and said channels between said second set of cross members in said second intermediate substrate intersecting to form second apertures bounded by said cross members in said second intermediate substrate, said second intermediate substrate being adjacent to said intermediate substrate and said second apertures in said second intermediate substrate being shifted from said apertures in said intermediate substrate to define a fluid path through said apertures in said first and second intermediate substrates, said fluid path being narrower than a narrowest dimension of either of said apertures in said first or second apertures in said second intermediate substrate; and 
 a fluid contained within said thermal ground plane for transporting thermal energy from a region of the said thermal ground plane to another region of the said thermal ground plane, wherein said fluid is driven by capillary forces in at least two directions along said channels between cross members of each said intermediate substrate. 
 
     
     
       2. The thermal ground plane of  claim 1 , further comprising a backplane opposite to and spaced from said metal substrate said backplane including supports extending from said backplane to one of said intermediate substrates nearest said backplane. 
     
     
       3. The thermal ground plane of  claim 2 , wherein said surface of said substrate within said vapor chamber includes a wicking structure having a plurality of grooves and said grooves are in communication with said apertures of said intermediate substrates. 
     
     
       4. The thermal ground plane of  claim 1 , wherein said first and second set of cross members are orthogonal with respect to each other. 
     
     
       5. The thermal ground plane of  claim 1 , wherein said intermediate substrates acts as the only wicking structure. 
     
     
       6. A thermal ground plane comprising:
 a metal substrate having a surface within a vapor chamber; 
 a first intermediate substrate within said vapor chamber overlying said surface of said metal substrate and having a first set of cross members in one direction and a second set of cross members in another direction, said first set of cross members being in a separate and adjacent plane from said second set of cross members, said first set of cross members defining channels between adjacent cross members within said first set, and said second set of cross members defining channels between adjacent cross members within said second set, said channels between said first set of cross members and said channels between said second set of cross members intersecting to form first apertures bounded by said cross members; 
 a second intermediate substrate within said vapor chamber overlying said first intermediate substrate having a first set of cross members in one direction and a second set of cross members in another direction, said first set of cross members being in a separate and adjacent plane from said second set of cross members, said first set of cross members defining channels between adjacent cross members within said first set, and said second set of cross members defining channels between adjacent cross members within said second set, said channels between said first set of cross members and said channels between said second set of cross members intersecting to form second apertures bounded by said cross members, said apertures in said second intermediate substrate are offset from said apertures in said second intermediate substrate to define a fluid path through said apertures in said first and second intermediate substrates, said fluid path being narrower than a narrowest dimension of either of said apertures in said first or second intermediate substrates; and 
 a fluid contained within said thermal ground plane for transporting thermal energy from a region of the thermal ground plane to another region of the said thermal ground plane, wherein said fluid is driven by capillary forces in at least two directions along said channels between cross members of said intermediate substrates. 
 
     
     
       7. The thermal ground plane of  claim 6 , further comprising a backplane opposite to and spaced from said metal substrate said backplane including supports extending from said backplane to said intermediate substrate nearest said backplane. 
     
     
       8. The thermal ground plane of  claim 7 , wherein said first and second sets of cross members in one of said intermediate substrates are orthogonal with respect to each other. 
     
     
       9. The thermal ground plane of  claim 6 , wherein said intermediate substrates act as the only wicking structure. 
     
     
       10. The thermal ground plane of  claim 6 , wherein said surface of said metal substrate within said vapor chamber includes a wicking structure having a plurality of grooves and said grooves are in communication with said apertures of said intermediate substrates. 
     
     
       11. The thermal ground plane of  claim 10 , wherein said surface of said metal substrate includes ridges, and said ridges contacting said intermediate substrate adjacent to said ridges.